[racket] understanding racket exceptions

From: Danny Yoo (dyoo at cs.wpi.edu)
Date: Tue Sep 7 11:33:20 EDT 2010

On Sat, Sep 4, 2010 at 10:26 AM, Matthew Flatt <mflatt at cs.utah.edu> wrote:
> The current exception handler really is determined by a continuation
> mark and not by a parameter (i.e., a mark that is separate from the one
> that determines the current parameterization).

Ok, I think I understand a little better now!  So there's some magic
'#%paramz module that defines an exception-handler-key that's used
throughout the system.  Ah, and I see that in the C implementation,
this is scheme_exn_handler_key, and the Racket runtime does special
things when an exception happens in the context of this distinguished
continuation mark.  Ok, that makes sense.

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